Gear cutting machine



M. MAAG. GEARCUTTING MACHINE. APPLICATION FILED DEC 22,191.9

ReissuedJuvly 6,

@Hoznu M. MAAS. yGEAR CUTTING MACHINE. APPLICATION FILED DEAC 22I, 1919.

Reissuod July 6, 1920 IIIIII IIIIIIIIIIIII .nl

"mnu Il II II II n lull ||||||||||H| -mm up UNITED STATESV MAiXilIAAGr,`OF ZURICH, SWITZERLAND.

GEAR-CUTTING MACHINE.

Specification of Reissued Letters Patent. Reissued J 6, 1920.

VYoriginal No. 1,270,183, dated :rune 1s, 1918, serial No. nana-meaAugust 2, 191e. Application for reissue ined December v22, 1919. serialNo. 346,791.

To all whom it may concern Be it known that I, MAX MAAG, a citizen ofthe Republic of Switzerland, residing at Zurich, Hardstrasse 219,Switzerland, have invented new and useful Improvements 1nGear-CuttingMachines, of which the following is a specification.

This invention relates to improvements 1n gear cutting machines workingaccording to the rollingprinciple.l The blank carrier of the machineforming the subject-matter of i this invention carries out a successiverolling movement during the cutting or planing operation which isfollowed by a backward rolling movement, a straight returnYV movementwithout rotation, and finally a return and forward `rolling movement totake up the play in the driving members. The se movements are controlledby acentral main drum rotating continually in the' same direction and byan auxiliary drum adapted to be moved in both directions. The auxiliarydrum initiates the arresting and restarting of the revolving movement ofthe blank carrier. All the other movements of the blank carrier arecontrolled by the central drum.

The object of the invention is to provide means such as the aforesaidauxiliary drum for arresting and restarting 'the revolving movement ofthe carrier.

The accompanying drawings show, by way of example, one embodiment of thepresent invention.

Figure 1 is a front view of the machine.

, Fig. 2 is a horizontal section.

Fig. 3 shows a planet gear adapted to stop and transmit a revolvingmovement to the blank-carrier. V

Fig. 4 shows a drum for controllingthe movement of the planet gear.

Fig. 5 shows t-he planet gear in connection with the drum controllingthe movement of said gear. i F'g. 6 is a controlling mechanism actuatedby the main control-drum.

Figs. 7 and 8 are details.

1 is the frame of the machine. In this frame is mounted the shaft 2carrying the main driving disk 2. Shaft 2 is operatively connected to ashaft 3 'by means of a bevel gear. A spur gear shown in Fig. 1 in dottedlines transmits the motion of the shaft 3 to the shaft 5, while a crankdrive transmits the motion of this shaft 5 to the tool carrier 6 adaptedto slide in a vertical guide. 7 denotes the rack-like tool fixed in saidcarrier 6 (Fig. 7). The motio'nof the shaft 5 isy also transmitted bymeans of toothed wheels 8 to a crank drive'9 adaptedto impart 'anoscillating movement to a slotted piece 10. The slide moving in the slotof the piece 10 is connected toa `plate 12 by means of a rod 11. Theplate 12 carries a pawl -13 adapted to engage a ratchet wheel 14 looselymounted on a shaft 15. To this shaft is fixed a pulley 16 and anotherpulley J18 is loose on shaft2. belt 17 runs over the pulleys 16 and 18.The pulley 18 is formed integral with the main driving disk 2 and theshaft 2 is adapted to be coupled to the parts 2. 18 by pressing a clutchmember 22 (Fig. 8) adapted to be moved longitudinally on theshaft 2, towhich it is keyed, into a recess of the pulley 18. Such a longitudinal'displacement of the member 22 ma be effected by pressing a lever 23upwar said lever being pivotally connected to one end of a bell-cranklever 2*, the other end of the latter beingconnected to the member 22.

A toothed wheel 19 formed integral with the ratchet wheel 14 engages atoothed wheel 20 fixed to a shaft 33. 23 denotes the main control-drumprovided with a spur wheel 24, which meshes with a toothed wheel 26fixed to a shaft 25. 27 and 28 denote Spur wheels, which drive the drum23 only when the momentary direction of rotation of each of said wheelsis such that the parts of the clutches 29' and 30 having oblique teethare able to grip. The toothed wheels 27 and 28 are driven by wheels 31and 32 respectively mounted on the shaft 33. Wheel 31 is rigidlyconnected to the sleeve 21 and wheel 32 to the sleeve 21a. During thecutting or planing operation the shaft 33'is driven by wheel 2() movedsuccessively and slowly by vthe ratchet mechanism 13, 14. During theremaining time of a course of work the tool movementand the feedmovement are ar-v rested and in this case the toothed wheel 34 is drivencontinuously vand quickly `by the constantly rotating pulley 16, anintermediate vgear being provided for this purpose. AThis wheel 34loosely mounted on the shaft 33- is adapted to be coupled to this shaft33` by means of a clutch 35 provided with the clutch 35 effects thethrowing out of gear. On the shaft 33 are further mounted loosely bevelwheels 39 and 40,v wheel 39 'being formed integral with sleeve 21,*wh1lewheel 4() is formed integral with sleeve 21".`

These wheels 39, 40 are adapted to be coupled separately to the shaft 33by means of a clutch 41 acted upon by a lever 42 pivotally mounted at43. A fork shaped lever shaft 51. lThe latter carries a drum 52 hav- 44connects the clutch 41 to the lever 42 and as one end of said lever 44lies between two projections 45, 46 of the lever 42 the movev that themovement of the latter is controlled by said drum.

The rotation of the bevel wheels 39, 40 is transmitted to a bevel wheel50 fixed to a l ing a recess 53 extending from oneend wall of lthis drumto the other one. Springs 52,a have the tendency to press the drum 52toward the bearing 54. The rotation of the shaft 51is transmitted bymeans of toothed wheels 55 to a shaft 56. 57 denotes planet bevel wheelsadapted to rotate about the shaft 56 and meshing with a bevel wheel 58fixed to the shaft 56 and a bevel wheel 59v loosely mounted on saidshaft 56. A spur wheel 60 s rigidly connected to the bevel wheel 59 andtransmits the motion of the shaft 56 to a shaft 61 as soon as the ring62 surrounding the planet wheels 57 is held stationary. This is effectedfrom time to time by the nose 63 projecting in this case into a slot 64(Fig. 3) of the ring 62. The

nose 63 is formed integral with a lever 65V pivotally mounted on the pin66 and carrylng at its outer end .a roll 67 working togjether with therecess 53 of the drum 52.

pon one rotation of this drum 52 in the direction ofthe arrow 68, and ifit is assumed that roll 67 rests on that end of this drum which liesadjacent the bearing 54, the lever 65 will be oscillated in acounterclockwise direction as soon as the roll 67 enters into the recess53, so that the nose 63 is drawn out 0f the slot 64 ofthe ring 62. Upona rotation of the drum 52 in the direction of the arrow 69, and if is itassumed that the roll 67 is now resting on the righthand side end of thedrum 52, as shown in Fig. 5, the lever 65 is then rocked in aclockwisedirection until the nose 63 enters again into the slot 64, andas this lever is then prevented from being moved farther toward theleft, the drum 52 is shifted during the further movement of the roll 67in said slot 53 toward the right against the action of the springs 52, l

, The rotation of the shaft 56 is transmitted to change wheels 70, 7172, the screw threaded Shaft 74 and the ma i5 0f the Slide 7o 76carrying the blank A, thus causing a displacement of said slide 76 inthe direction of the double arrow 77, 78;

On the shaft 61 provided with a key-way is movably mounted a worm 79meshing with the worm wheel 80 of the table 81 carryingthe blank. Thetable 81 is movably mounted on a gudgeon 82 of thel slide 76.

The hereinbefore described machine works as follows: During the cuttingor I planing 80 loperation the shaft 3 isl coupled to the main drivingdisk 2 and thev ratchet wheel 14 actua-tes the main control-drum 23 andthe separate drum 52 and effects at the same time by means of the shaft51 the rolling movement vof the table 81 supporting the blank. Upon thissuccessive forward movement of the table 81 follows its return movementfilling up the remaining part of the course of work. This returnmovement consists of a short backwardrolling movement I, a backwardtravel vII without rotation corresponding to the forward travel duringthe cutting operation, a second short backward rolling movement III-andfinally a forward rolling movement IV corresponding to the sum of thetwo short backward rolling movements andserving to take up the play inthedrivingmembers. The continuously rotating pulley 16 actuates themembers. effecting the 100 different return movements. The maincontrol-drum 23 performs one revolution dur-v ing one course of work.The cutting operation lasts 4/1() of a. revolution of the. maincontrol-drum and the several return movements together 6/10, namely':

Motion I 1/20 Motion II 4/10 kMotion III 1/20 1'10 Motion, IV 1/10 Shaft51 is thus rotated in the direction of 120 I arrow 84. The separate drum521" is also rotated and is kept during this movement in its righthandend position near the spur wheel 55, while the roll 67 of lever- 65rests on the left-hand end wall of drum 52, so

that the nose 63 of lever 65 projects into the slot 64 of the ring 62and the shaftsv of the planet bevel whee1s-57 arie prevented fromrotating about the shaft 56. The' bevel wheel 59 is thus rotated andtherefore also 130 the shaft 61. The latter imparts thereby ,-i'a rotarymovement to the blank. Upon each feed movement of the shaft 51 also thevwheels 70, 71, 72 are setin motion and consequently also shaft 74. Thetable 81 .is thus rotated each time in the direction of arrow 85 and isshifted at the same time i the direction of arrow 78.

At the end of the last feeding stroke of the cutting period the cam 48of the drum of the parts 41 and 39 has the effect to impart to the shaft51 a movement in the direction opposite to the direction of lthe arrow84, so that also the direction of rotation of the separate drum 52 ischanged.

- In the meantime the roll 67, which is lying on the end wall of thedrum 52 adjacent the bearing 54, moves toward the recess 53, whichcauses an oscillation lof the lever 65 in a counter-clockwise direction,so that, when the roll 67 falls into the' recess, the

j nose 63 is pulled out of the slot 64 of the ring 62. I

This occurs just at the time, at which the main control-drumcompletes1/20 of its revolution and during which the blank carrier table81 has effected a backward rollingr movement in the direction ofarrow8G. As soon as the. nose G3 `lleaves the slot G4, the ring 62surrounding the planet wheels 57, is, however, able to rotate freely.The bevel wheel 59 and the corresponding change wheels then remainstationary and the table ceases to rotate, while the travel of the tablein the direction of arrow 77 is continued during the following 4/10 of arevolution of the main control-drum 23.

During this time the roll G7 is moved again into the recess 53, theseparate drum 521being constantly rotated. As the ring G2 has justcompleted one revolution, the `nose G3 falls again into the slot G4arresting the ring 62. The result of this is, that the table 81 is againrotated, so that a second backward rolling movement is imparted to itlasting again 1/20 of a revolution of the main control-drum 23. Afterthe exn pil-ation of this time the cam 47 of the main control-drum 23pushes the levers 42 and 44 in such a manner sidewise, that the bevelwheel 39 is again uncoupled from the shaft 33, while the bevel wheel 4()is coupled to it. The shaft 51 rotates now in the opposite direction,that is in the direction of the arrow j before.

At the same time the lever 38 runs off 84, so that the teeth of theclutch 29 slide again over one another, while the teeth of the clutch 30are meshing.

It will be seen, that the main controldrum is still moved in the samedirection as The separate drum 52 changes, however, its direction of`rotation together with the shaft`51 and the roll 67 comes to rest onthe end wall of the drum 52 lying adjacent the bearing 54, so that thedrum 52 is shifted toward the spur wheel 55, while the nose vb3 remainsin the slot 64. A forward rolling movement is' thus imparted to theltable 81 lasting 1/10 of a revolution of the-main drum 23. i f

The preceding backward rolling lmovements lasting 2x1/2() of arevolution of the drum 23 and this forward rolling movement lasting 1/10of al revolution of said drum take up the clearance in the drivingmembers, so that theJ cutting operation may now again be started. Theforward rolling movement is arrested as soon as the end of cam 37provided on the main control-drum 23 comes to lie beneath the lever 38.The

latter then throws the clutch 35 out of gear and .at the same time` theIshaft 3 is coupled to the main -drive by means of members not shown 1nthe drawings, so that the tool movement, thel feeding movement, andtherefore also the successivev rolling movement of the table are againstarted.l

A machine of the same general type as that hereindisclosed is set forthin my Patent No. 1,290,270, dated January 7, 1919. I do not, therefore,herein present broad claims for' the machine, but only claims for thosefea-tures wherein the` present machine differs from the machine rsetforth inthe m5 said patent.

lVhat I claim is:

1. In a gear cutting machine working according to the rolling principle,in combination, a tool holder, a blank-carrier, means for moving thetool holder, and imparting to the blank-carrier a rotary movement and alongitudinal travel, said means comprising two separate drums forcontrolling the movements of the blank-carrier, and means actuated byone of said drums for influencing the movement of the other drum,substantially as described;

2. In a gear cutting machine working according to the rolling principle,in combination, a tool holder, a'blank-carrier, means for moving thetool holder and impartingl to 3. In a gear cutting-machine 'workingaccording to the rolling principle, in combinaftion, a cutting tool, atool holder, a support for the work piece, means for moving the toolholder, a main'control-drum, an auxiliary control drum, means adapted toimpart a revolving movement and a longitudinal travel to the support forthe work piece and -actuate said' main drum, the latter controllingthereby direction' of said movements and means for transmitting themovement of the main drum to the auxiliary drum and adapted to rotatethe latter in both direc-'- Afor moving the tool holder,a maincontroldrum, an auxiliary ,control-drum, means adapted to impart arotary movement and a longitudinal travel to the blank-carrier andactuate said main drum, the latter controlling thereby the direction ofsaid movements, means for transmitting rthe moves ment of the main drumto the auxiliary drum, and means effecting at determined intervals inconnection with the auxiliary drum an arresting and restarting of therotary movement of the blank-carrier without influencing the straight,longitudinal travel of said blank-carrien,substantially as-de scribed.

l5. In a gear cutting machine working according to the rollingprinciple, in combination, a tool holder, a blank-carrier, a main drive,means actuated by the latter for Inoving the tool holder, a maincontrol-drum, an auxiliary control-drum, means actuated by the maindrive for moving said drulns and imparting to the blank-carrier a rotarymovement and a longitudinal travel, these.

means being actuated at different speeds during the'cutting operationand thereturn movement of said blank-carrier, and means actuated by saidmain control-drum for controlling the movement of the auxiliary drum,substantially as described.

6. In a gear cutting machine working aci cording to the rollingprinciple, in combination, a cutting tool, a tool holder, a support forthe work piece, a main driving member, means actuated by the latter formoving the tool holder, an auxiliary shaft, means adapted to transmitthe movement of said main. driving member at different speeds to saidauxiliary shaft, `a main control-drum, means for transmittingl themotion of said auxiliaryshaft to this drum, a second auxiliaryl shaft,an auxiliary control-drum mounted on this shaft, means for transmittingthe motion of the first auxiliary shaft to the4 second one, .meanscontrolled by the main drum for chanomsr the direction of rotation ofthe second auxiliary shaft, and gears driven by the second auxiliaryshaft imparting a rotary movement and a longitudinal travel to thesupport for the work piece,

substantially as described.

7. In a gear cutting machine working acy cording to the rollingprinciple, in combination, a cutting tool, a tool holder, a' supportvfor the work piece, a main driving member,

driving member at one speed to said fixed wheel and at another speed tosaid loosely mounted wheel, a main control-drum, two gearseach providedwith a clutch adapted to transmit Athe motion of said auxiliary shaft tothe control-drum, two bevel wheels .loosely mounted on said auxiliaryshaft, a

sliding clutch member fixed to the latter and mounted between said twobevel wheels, a second auxiliary shaft, an auxiliary con- Jtrol-drumfixed thereto, a bevel wheel fixed to the second auxiliary shaft andmeshing with the two first mentioned bevel wheels, a movable membercontrolled by the main drum adapted to move said clutch member mountedon the first mentioned auxiliary shaft into gear with one of the bevelWheels mounted on the latter shaft, means` controlled by the maincontrol-drum adapted to rigidly connect said spur wheel to the lastmentioned' auxiliary shaft and gears driven by the second auxiliaryshaft imparting a rotary movement and a longitudinal travel to thesupport for the work piece, substantially as described.

8. In a gear cutting machine working according to the rolling principle,in combina# tion, a cutting tool, a tool holder, a support for the workpiece, a main control-drum, an auxiliary control-drum, a shaft carryingthe auxiliary drum and rigidly connected thereto, means for driving thedrums, means adapted t0 yso control the motion of the auxiliary drum bythe main drum, that the auxiliary drumj is rotated in two directions,while the main drum is constantly rotating in the same direction, aworm, a gear adapted to drive said worm, means transmitting the motionof the worm to the support for the work piece, a screw threaded .shaftworking together with a screw threaded part of said support, a gear fordriving the screw threaded shaft, means'adapted to transmit themotion'of the shaft carrying the auxiliary drum aswell to said worm andscrew threaded shaft as also only to this shaft, and means forcontrolling ,these movements from the auxiliary drum, substantially asdescribed.

' 9. In aA gear cutting machine working according to the rollingprinciple, inhcombination, a cutting tool, a tool holder, a support forthev work piece, a main control-drum, an auxiliary control-drum, a shaftcarrying the auxiliary drum and rigidly connected thereto, means fordriving the drums, means adapted toso control'the motion of theauxiliary drum by the main drum, that the auxiliary drum is rotated intwo directions,

in the same direction,y a worm, a screw threaded shaft working togetherwith a adapted to transmit the motion of the shaft carrying theauxiliary drum to said screw threaded shaft, a second gear actuated bythe last mentioned gear and driving said worm', said second gearcomprising two bevel wheels and a planet bevel gear work-4 ing togetherwith these two bevel wheels, and a locking device controlled by theauxiliary drum acting together vwith the planet gear, the arresting ofthe latter causing a rotation of the worm, which is then held stationaryas soon as the planet gear is released, substantially as described.

10. An automatic gear cutting machine comprising in combination, ablank-carrier, a tool holder normally reciprocating in a fixed path andadapted to hold a cutter of the rack type, mechanism operable by asingle reversible shaft for simultaneously turning the carrier forwardand for moving it rectilinearly forward whereby :a forward rollingmovement is effected and for reversing the said movements wherebybackward rolling is effected, means operable by the said shaft forinterrupting the backward turning by an amount equal to an integralnumber of pitches, and means for interrupting the normal operation ofthe tool holder in relation to the blank-carrier at the end of eachforward rolling movement and for ing movement.

11. An automatic gear cutting machine comprising in combination, ablank-carrier, a tool holder normally reciprocating in a fixed path andadapted to hold a cutter of the rack type, a carriage for theblank-carrier adjustable toward and from the tool holder, mechanismoperable by a single re- .versible splined shaft4 for simultaneouslyturning the carrier forward and for moving it rectilinearly forwardwhereby a forward rolling movement is effected and for reversing the'said movements whereby backward rolling is effected, means operable bythe said shaft for interrupting the backward turning by an amount equalto van integral number of pitches, and means for intero rupting thenormal operation of the tool holder vin relation t the blank carrier atthe end of each forward 'rolling movement while the main drum isconstantly rotating screw threaded part of said support, a gear startingthe said normal operation after the beginning of each succeeding forwardrolland for starting the said normal operation after the beginning ofeach succeedlng forward rolling movement.

12. An automatic gear cutting machine comprising in combination, ablank-carrier, a tool holder normally reciprocating in a fixed path andadapted A,to hold a cutter of the rack type, mechanism operable by asingle reversible shaft for simultaneously turning the carrier forwardand for moving-it rectilinearly forward whereby a forward rollingmovement is effected and for reversinfr the said movements wherebybackward ro ling is effected, means automatically operable by thereversal of the said shaft for interrupting the backward turning by anamount equal to an integral number of pitches, and means forinterrupting the noretv mal operation of the tool holder in relation tothe blank-carrier at" the en'd of each forward rolling movement and forstarting the said normal operation after the beginning .of eachsucceeding forward rolling movetion of the tool holdery in yrelation'tothe blank-carrier at the end of each forward rolling movement and forstarting the said normal operation after the beginningof each succeedingforward rolling movement.

14:. An automatic gear cutting machine comprising in combination, ablank-carrier,

'a tool holder normally reciprocating in a fixed path andladapted tohold a cutter of the rack type, mechanism including a screw and a wormfor turning `the blank-carrier and for moving it rectilinearly whereby aforward or backward rolling movement is effected, a single shaft foroperating the said screw and worm, means operable by the said shaft andcomprising planetary gearing for interrupting backward turning of theworm to a predetermined extent, and `means for interrupting the normaloperation of the tool holder in relation to the blank carrier at the endof each forward rolling movement and for starting the said normaloperation after the beginning of each succeedlng forward rollingmovement. y l y In testimony whereof Iv hereunto afiix my signature.

